Entry loss = 0.15 velocity pressure for tapered takeoff; 0.65 velocity pressure for straight takeoff. TABLE H-12-MAXIMUM ALLOWABLE SIZE OF CONTAINERS AND PORTABLE TANKS Container exemptions: (a) Medicines, beverages, foodstuffs, cosmetics, and other common consumer items, when packaged according to commonly accepted practices, shall be exempt from the requirements of § 1910.106(d)(2) (i) and ( Horizontal Single-Spindle Disc Grinder Exhaust Hood and Branch Pipe Connections NOTE: If grinding wheels are used for disc grinding purposes, hoods must conform to structural strength and materials as described in 9.1. Entry loss = 0.45 velocity pressure for tapered takeoff. Entry loss = 0.45 velocity pressure for tapered takeoff; 0.65 velocity pressure for straight takeoff. (6) Scope. This paragraph (b), prescribes the use of exhaust hood enclosures and systems in removing dust, dirt, fumes, and gases generated through the grinding, polishing, or buffing of ferrous and nonferrous metals. em (c) Spray finishing operations—(1) Definitions applicable to this paragraph—(i) Spray-finishing operations. Spray-finishing operations are ployment of methods wherein organic or inorganic materials are utilized in dispersed form for deposit on surfaces to be coated, treated, or cleaned. Such methods of deposit may involve either automatic, manual, or electrostatic deposition but do not include metal spraying or metallizing, dipping, flow coating, roller coating, tumbling, centrifuging, or spray washing and degreasing as conducted in self-contained washing and degreasing machines or systems. (ii) Spray booth. Spray booths are defined and described in § 1910.107(a). (See sections 103, 104, and 105 of the Standard for Spray Finishing Using Flammable and Combustible Materials, NFPA No. 33-1969). (iii) Spray room. A spray room is a room in which spray-finishing operations not conducted in a spray booth are performed separately from other areas. (iv) Minimum maintained velocity. Minimum maintained velocity is the velocity of air movement which must be maintained in order to meet minimum specified requirements for health and safety. (2) Location and application. Spray booths or spray rooms are to be used to enclose or confine all operations. Spray-finishing operations shall be located as provided in sections 201 through 206 of the Standard for Spray Finishing Using Flammable and Combustible Materials, NFPA No. 33-1969. (3) Design and construction of spray booths. (i) Spray booths shall be designed and constructed in accordance with § 1910.107(b) (1)-(4) and (6)-(10) (see sections 301-304 and 306-310 of the Standard for Spray Finishing Using Flammable and Combustible Materials, NFPA No. 33-1969), for general construction specifications. For a more detailed discussion of fundamentals relating to this subject, see ANSI Z9.2-1960 |